1. Field of the Invention
The present invention relates to a belt-like LED light.
2. Description of the Related Art
Upon turning on a plurality of LEDs (Light-Emitting Diodes) of an SMD (Surface Mount Device) type having been linearly mounted on a circuit substrate, a light-emitting direction is generally a direction perpendicular to the circuit substrate. If the circuit substrate is manufactured using a belt-like FPC (Flexible Printed Circuit) which is easily bent, the light-emitting module itself can be also bent against the light-emitting direction. Such goods have been manufactured and commercially available as “tape lights.”
According to this structure, unless the belt-like light-emitting module is twisted, it is difficult to bend the module in a direction (lateral direction of the belt-like FPC) perpendicular to the light-emitting direction of the LEDs. The FPC must have width no less than 7 millimeters in order to mount parts thereon to form a circuit. So, the module cannot be bent in the lateral direction.
In order to bend the FPC substrate in the lateral direction perpendicular to the light-emitting direction, LEDs of a side emission type or a bullet-type may be used. When the side emission type LEDs are used, since the light-emitting direction of the LEDs is the width direction of the substrate, the belt-like substrate of the FPC can be bent in the lateral direction perpendicular to the light-emitting direction. This is the same as the bullet-type LEDs. Reference 1 (Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2004-526185), Reference 2 (Registered Japanese utility model No. 3098840), and Reference 3 (Registered Japanese Patent No. 3897260) disclose examples of flexible light-emitting modules using the bullet-type LEDs.
As an example not using the FPC, Reference 4 (Japanese patent application Laid-open on No. 9-297549) recites a flexible linear light-emitting module configured as follows. That is, two or more pairs of positive and negative feeders are arranged in a spiral or intersected state. A plurality of LEDs and current-limiting resistances are in series connected between the pairs to configure a series circuit. One or more of the series circuits are connected in parallel. And then, the feeders and so on are covered with soft and translucent synthetic resin to configure the flexible linear light-emitting module.
Reference 5 (U.S. Pat. No. 7,377,787) proposes an illumination device, comprising: electrical components (LEDs);
a tabbed circuit substrate on which the LEDs are mounted and operably connected; and
a light-diffusing member for receiving light emitted from the LEDs, wherein:
the tabbed circuit substrate includes:
a flexible substrate of a predetermined length;
a conductive trace formed on the flexible substrate; and
tabs arranged along a lateral edge of the flexible substrate,
one or more of the electrical components are connected to the conductive trace at respective tabs, and
the tabs can be bent from a first position in which the tabs are aligned with the remainder of the substrate to a second position in which the tabs are oriented at an angle (90 degrees) relative to the remainder of the substrate.
As mentioned above, even if the LEDs of the surface mounting type have been mounted on the FPC, light is always emitted in the lateral direction perpendicular to the FPC surface. That is, light does not always emit in a shape that the FPC is bent.
Whereas, upon using the LEDs of the side emission or the bullet-type, light is always radiated in a shape that the FPC is bent. Variation in luminance and color of those, however, is so poor that various customer needs cannot be satisfied thereby. This is because the LEDs of the side emission or the bullet-type are not used except for particular application.
Reference 4 discloses the flexible linear light-emitting module not using the FPC. Due to this, a step of mounting LEDs thereon and another step of twisting feeders are needed. So, there are some problems in mass production.
Reference 5 discloses the circuit substrate and the lighting system using the same. Herein, there is a problem that a part of light emitted from the LEDs is blocked by the circuit substrate itself when the LEDs are positioned lower than the circuit substrate. This is because the LEDs are mounted the inside of the tabs having been bent perpendicularly to the circuit substrate.
When the LEDs are mounted outside of the tabs, the whole of the lighting system becomes too high. This is because both of the LEDs and the light-diffusing member must project toward the outside of the tabs.
In Reference 5, the LEDs are mounted at positions shifted from the circuit substrate. When the LEDs are arranged on the center line, the circuit substrate must be shifted from the center line. Accordingly, upon using in a bent state, there is a problem that the circuit substrate must undergo stress.
Furthermore, in order to supply electric current to the LEDs mounted on the tabs, the conductive traces are formed on the circuit substrate. In Reference 5, since on the common circuit substrate, all conductive traces for positive and negative sides are formed, the width of the circuit substrate cannot be narrower than a fixed size. Accordingly, downsizing the circuit substrate is remarkably limited.
In view of the above, in Reference 6 (Japanese patent application Laid-open on No. 2013-118169), the applicant has proposed a belt-like LED light, comprising:
a LED-mounting circuit substrate;
a light-emitting unit; and
transparent or translucent flexible insulation material covering the light-emitting unit,
the LED-mounting circuit substrate including:
a long belt-like flexible substrate;
a LED-mounting portion that LEDs are mounted in an array state on a center portion in a width direction of the long belt-like flexible substrate; and
a first substrate and a second substrate including at least two feeding patterns for feeding electric current to the LEDs, the first substrate and the second substrate being positioned at both sides of the LED-mounting portion in the width direction, wherein:
the light-emitting unit is formed by:
mounting the LEDs and electrical parts on the LED-mounting circuit substrate; and
folding at least one of the first substrate and the second substrate against the LED-mounting portion.